Ok

Originally Posted by chrozer

No..sorry. The question just said what I posted earlier.

MathStud: I have no idea what u did there.

What I was doing was not showing you the extraneous answer in this problem but what would make an extraneous answer...because if we got a number x such that x-5<0 then we would have a problem because we would have lets say x=-3 then we would have since its well known that

What I was doing was not showing you the extraneous answer in this problem but what would make an extraneous answer...because if we got a number x such that x-5<0 then we would have a problem because we would have lets say x=-3 then we would have since its well known that

Oh ok. I didn't know that .

Originally Posted by Soroban

Hello, chrozer!

Quadratic Formula: .

There are two roots, one of them is: .

The radical is: .

This makes negative, an extraneous root.
. . [We cannot have the log of a negative quantity.]

Hence, the only root is: .
. . The other is always extraneous.

Why did you get rid of the in the equation in the radical part?

I also asked someone else about this question and he explained it this way:

If the roots of this equation were to be real,
If , the solution wouldn't be real.